This invention relates to the selective identification of work pieces and more particularly to the marking of work pieces to facilitate their identification during use.
Many work pieces, such as wrenches, are available in a wide variety of sizes. In the case of so called "end" wrenches, it is common practice to have a complete assemblage with successive graduations. For example, in the case of open-end and box-end wrenches with metric openings, the successive wrenches can cover the gamut from 5-25 millimeters. An opening of 5 millimeters is difficult to distinguish from an openings of 6 millimeters. A similar consideration applies to tools and wrenches which bear English gradations. Thus, a wrench with a 9/16th opening is difficult to distinguish from the next larger or smaller size which may be 1/2 or 5/8.
In order to distinguish among the various sizes is it common practice to mark the wrenches by stamping, which desirably produces an impression in the tool. This procedure is satisfactory when size markings are readily visible. In many situations, however, for example, where a mechanic is working on an automobile, he may want to reach for the tool without having to focus on the size marking.
Accordingly, it is an object of the invention to facilitate the identification by size of similar sized work pieces and tools. A related object is to facilitate the individual identifications of socket, box end and open end wrenches which have approximately the same size openings.
Another object of the invention is to permit a user to quickly select a tool of the desired size without having to view either the opening of the tool or the size stamped on the tool.